The ED treatment goal is the elimination of intrapleural air. Tension pneumothorax should be diagnosed clinically—before a radiograph—and immediately treated by needle decompression followed by tube thoracostomy.
Treatment options are oxygen, observation, needle or catheter aspiration (either single or sequential aspirations), and tube thoracostomy (either small-size or standard chest tube) (see Tables 68-2 and 68-3). Oxygen administration (>28%) increases pleural air resorption three- to fourfold over the base 1.25% reabsorbed per day, by creating a nitrogen gas pressure gradient between the alveolus and trapped air.19,20,21 Without supplemental oxygen, a 25% pneumothorax would take approximately 20 days to resolve. Recommended dosing ranges from 3 L/min nasal cannula to 10 L/min by mask and should be guided by the patient's status. Monitor for hypercapnia in patients with chronic obstructive pulmonary disease.
Observation is appropriate for small, stable pneumothoraces only. If this option is selected, observe the patient for at least 4 hours on supplemental oxygen, and then repeat the chest radiograph. If symptoms and chest radiograph improve, the patient should return in 24 hours for repeat examination. First-time spontaneous pneumothorax of <20% lung volume in a stable, healthy adult may be treated initially with oxygen therapy and observation.19,20,21,22,23,24
Aspiration or tube thoracostomy is selected based on likelihood of recurrence and likelihood of spontaneous resolution. Pneumothoraces in patients with underlying pulmonary disease are likely to recur. Large pneumothoraces and those with an air leak are unlikely to resolve without drainage. Inability to return for care or to tolerate any pneumothorax increase (i.e., those with poor cardiopulmonary reserve) should prompt drainage.
When deciding to intervene procedurally on a pneumothorax, the stability of the patient, the degree of symptoms, the size and relative change in size over time, the cause of the pneumothorax, the degree of underlying lung disease, the likelihood of recurrence and resolution, and the need for positive-pressure ventilation are factors to consider. In situations when the patient is clinically stable (Table 68-2), various treatment approaches can be considered (Tables 68-3 and 68-4).18,19,20,21,22,23,24,25,26,27
TABLE 68-2Criteria for Stable Patient with Pneumothorax ||Download (.pdf) TABLE 68-2 Criteria for Stable Patient with Pneumothorax
Respiratory rate <24 breaths/min
No dyspnea at rest, speaks in full sentences
Pulse >60 and <120 beats/min
Normal blood pressure for patient
Room air oxygen saturation >90%
Absence of hemothorax
TABLE 68-3Aspiration and Thoracostomy Devices* ||Download (.pdf) TABLE 68-3 Aspiration and Thoracostomy Devices*
|Single aspiration ||Insertion of a needle or catheter, aspiration of air using an attached syringe, and immediate removal of the device |
|Needle aspiration ||18-gauge needle (provided in kits as an 8-French catheter over an 18-gauge needle) |
|Small-size catheter ||≤14 French |
|Small-size chest tube ||10–14 French |
|Pigtail catheter ||14 French, placement using Seldinger technique |
|Moderate-size chest tube ||16–22 French |
|Large-size chest tube ||24–36 French |
TABLE 68-4Treatment of Pneumothorax ||Download (.pdf) TABLE 68-4 Treatment of Pneumothorax
|Condition ||Treatment Options |
|Small primary pneumothorax (<20% or 3 cm apex-cupula and asymptomatic) || |
Observation for >3 h on oxygen, repeat chest x-ray, discharge if no symptoms, and return for check if symptoms recur or in 24 h
Small-size catheter aspiration with immediate catheter removal, then observe for >3 h, discharge if no symptoms, and return for check if symptoms recur or in 24 h
Small-size catheter aspiration or small-size chest tube insertion, Heimlich valve, or water seal and admission
|Small secondary pneumothorax ||Small-size catheter or small-size chest tube insertion, Heimlich valve, or water seal and admission |
|Large pneumothorax, either primary or secondary, or bilateral pneumothoraces ||Moderate-size chest tube and admission; large-size chest tube if fluid or hemothorax present; water seal and admission |
|Tension pneumothorax ||Immediate needle decompression followed by moderate or large-size chest tube insertion, water seal drainage, and admission; immediate chest tube placement ideal |
The selection of catheter or chest tube size is based on the flow rate of air that the device can accommodate. Select large-bore tubes for anticipated big leaks, as from mechanical ventilation. Tension pneumothorax can develop if a large air leak develops, and small-bore tubes or catheters cannot handle the air flow. Every chest tube has a proximal hole, called the sentinel eye, which is visible radiographically and helps ensure that all drainage holes are inside the pleural cavity. Table 68-3 provides definitions for terms and various devices used to treat pneumothorax.26,27,28,29,30
To decompress, wear protective clothing or at least a mask to prevent material from squirting onto the operator. Use a 14-gauge needle for adults and an 18-gauge needle for children. Select a needle at least 2 inches (5 cm) long to penetrate the pleural cavity. Two locations are recommended: into the second or third intercostal space just above the rib (to avoid the intercostal artery) at the midclavicular line, or in the fourth or fifth intercostal space just above the rib and at the anterior axillary line (Figure 68-4). One small postmortem study analyzing both approaches reported only a 59% success rate in entering the pleural cavity.31 If the needle is inserted medial to the midclavicular line, mediastinal vessels can be injured. A finger cot cut at its distal end can then be placed over the needle to fabricate a one-way valve. The Heimlich valve is still occasionally used for ambulatory treatment of pneumothorax, and serious complications with its use are rare.32
Needle placement for decompression of a right-sided tension pneumothorax. A site for a needle thoracostomy is the second intercostal space in the midclavicular line. [Reproduced with permission from Reichman EF, Simon RR: Emergency Medicine Procedures. © 2004, McGraw-Hill, New York.]
NEEDLE OR CATHETER ASPIRATION
Needle or catheter aspiration is as effective as thoracostomy for treating the first episode of small primary or secondary spontaneous pneumothorax,25 with success ranging from 37% to 75%, or higher in those with primary spontaneous pneumothorax.26 Techniques include simple one-time aspiration with a large-gauge needle or a small-bore catheter, repeated aspirations through a small-size catheter, or chest tube attached to a one-way valve or water seal drainage. The catheter technique has the advantages of both aspiration and chest tube placement.27
The catheter technique involves placing a small catheter either into the second anterior intercostal space in the midclavicular line or laterally at the fourth or fifth intercostal space in the anterior axillary line after local anesthesia and sterile preparation. Attach a three-way stopcock, and use a 60-mL syringe to aspirate the pleural space until resistance is met, often triggering a cough. Close the stopcock, secure the tube, and obtain a follow-up chest radiograph to ensure lung reexpansion. Aspiration of more than 4 L suggests continued air leak and failure of simple aspiration. Failure of the lung to fully expand warrants another aspiration attempt or formal tube thoracostomy and admission.
Pigtail Catheters Using Seldinger Technique
Advantages of this technique are a smaller incision, less tissue dissection, and smaller scar.
Insert the needle into the pleural space, making sure placement is in the "triangle of safety" (Figure 68-5).29,32 Aspirate fluid or air to verify location in the pleural space, and advance a guidewire through the needle. Place a dilator over the guidewire until the pleural space is entered. Remove the dilator and place the chest tube over the wire into the pleural space. Remove the stylet, secure the tube, and attach to suction.
Safe location of chest tube, within a triangle bordered by the fifth intercostal space, pectoralis major, and latissimus dorsi.
Chest tube thoracostomy is used to treat a large pneumothorax, recurrent or bilateral pneumothorax, or coexistent hemothorax, or if there are abnormal vital signs or dyspnea. A chest tube is used in small spontaneous secondary pneumothoraces where large air leak is anticipated or noted. Standard chest tube thoracostomy with underwater seal drainage is the most commonly used approach, with a low complication rate and a success rate of 95%.24,25 Most guidelines suggest a small 10- to 14-French chest tube for nontrauma, reserving larger 14- to 22-French chest tubes if a large air leak is probable, such as from mechanical ventilation or with underlying pulmonary disease.
The technique of tube thoracostomy is described in the chapter 261, "Pulmonary Trauma."
There is no clear difference between simple aspiration and intercostal tube drainage in overall short- and long-term outcomes,24 and simple aspiration is as safe and effective as tube thoracostomy for small-volume air leak primary spontaneous pneumothorax.25